Shoe lasting machine



Dec. 9, 19 47. R. H. LAWSON SHOE LASTING MACHINE Original Filed March14,1945. 4 Sheets-Sheet 1 2 6 8 a 2 57/ f i 3 x J L. 6 H L J 6 b. 2 x4 0b 4 .4 p \4. v 3 o 0 mm flfl w U U lnvenfor Poberz H Lawson Dec. 9,1947. R. H. LAWSON I SHOE LASTING MACHINE Original Filed March 14, 19454 Sheets-Sheet 2 [fluemo Robert H-Lawsoh Dec. 9, 1947. R. H. LAws oN I2,432,165

SHOE LASTING MACHINE Original Filed March 14, 1945 4 Sheets-Sheet 3 Inuen ZOlf' Dec. 9, 1947. R, H, LAWS 2,432,165

SHOE LASTING MACHINE Original Filed March 14, 1945 4 Sheets-Sheet 4 Q 1N7 J7? A54 264 d 270 274 268 2 266 In van for Roberz H Lawsonhisfiffirzei Patented Dec. 9, 1947 SHOE LASTING MACmNE Robert H. Lawson,Beverly, Mass, assignor to United Shoe Machinery Corporation,Flemington, N. J., a corporation of New Jersey Original applicationMarch 14, 1945, Serial No.

1946, Serial No. 667,843

6 Claims.

This invention relates to shoe lasting machines and is hereinillustrated as applied to a welt shoe lasting machine of the typedisclosed in an application for United States Letters Patent Serial No.582,647, filed March 14, 1945, of which this application is a division.

Shoe lasting machines of the above identified type usually comprise alasting gripper adapted to tension a shoe upper over a last, and afastening inserting mechanism, including a throat member, adapted towipe the marginal portion of the tensioned upper into lasted relation toa sole member on the last bottom and thereafter to secure the marginalportion of the upper in lasted position.

It is sometimes desirable when operating on certain portions of certainkinds of shoes temporarily to dispense with the gripper operation. Or,sometimes, it may be desired to use the above identified machine purelyas a fastening inserting machine for the operation upon other types ofwork not calling for a gripper and a tensioning operation. It istherefore the purpose of this invention to provide an effective gripperthrowout mechanism easily operable at the will of the operator at anytime during the machine operation without interfering with the latter.

According to one feature of the invention there is provided a gripperthrow-out mechanism controlled by the operator and so acting on thegripper operating mechanism that the gripper jaws are locked againstclosing to prevent the seizing of the upper, whereupon the gripper ismoved to an inoperative position in which it is held as long as it isdesired to eliminate the gripper operation. In particular, the lockingof the gripper jaws against closing occurs when the gripper is in itslowermost position in readiness to seize the upper, whereupon thegripper is raised to an inoperative elevated position with its jawsopen, in which position it is held against downward movement.

These and other features of the invention will now be described withreference to the accompanying drawings and will be pointed out in theappended claims.

In the drawings,

Fig. 1 is a view in right hand side elevation of the principal parts ofa machine embodying the present invention, with certain parts of themachine broken away;

Fig. 2 is a view in right hand side elevation of mechanism for operatingthe fastening inserting mechanism;

Fig. 3 is a plan view of the machine illustrated in Fig. 1, with certainparts broken away;

Fig. 4 is a detail view of the throat member and associated mechanism;

Fig. 5 is a sectional view taken along the line VV of Fig. 4; and

Divided and this application May 7,

2 Fig. 6 is a detail view in plan of the gripper operating mechanism.

General organization of the machine The principal operatinginstrumentalities of the machine and their actuating mechanisms arecontained in or secured to a box-like frame 20 (Figs. 1, 2 and 3) whichis adapted to rest On a support (not shown). The principal work engagingoperating instrumentalities of the illustrated machine area stationaryanvil 22 (Fig. 1), an upper tensioning gripper 24, and a wiper 26through which the fastenings are inserted, by mechanism to be described,into the work. The work is a shoe comprising an upper U on a last L, thelast carrying on its bottom a ribbed or lipped insole I into lastedrelation with which the upper is worked and then secured in thisrelation by fastenings inserted through the margin of the upper and thelip of the insole. The shoe is manually presented to the machine in aposition in which the anvil 22 engages the rear face or inner side ofthe lip of the insole I on the bottom of the last L over which the upperU is to be tensioned by the gripper 24. The anvil 22, of course, iscaused initially to engage and support that portion of the insole lipwhere the fastening inserting operation is to begin, the operation beingrepeated and progressing along the lip first at one side and then at theother side of the insole while the shoe is held in the operators handsand is successively moved or fed by him with relation to the machine topresent diiferent portions of the shoe successively to the operatinginstrumentalities of the machine.

The actuating mechanisms of the various movable operatinginstrumentalities of the machine are driven from a single cam shaft 28(Figs. 1, 2 and 3) extending transversely of the machine and arrangedfor rotation in suitable bearings provided in the frame 20. The camshaft 28 is driven by connections (not shown) to a suitable source ofpower, the connections including an operator controlled clutch (notshown) which, when maintained engaged, will continue to rotate the camshaft and thus cause the machine to run through an indefinite number ofcycles, one cycle corresponding to one complete revolution of the camshaft.

The gripper mechanism For tensioning the upper U of a shoe presented tothe machine in the position illustrated in Fig. 1, heightwise of thelast, the illustrated machine is provided with the previously mentionedgripper 24 comprising two jaws 30 and 32 which are rotatable about acommon pivot pin 34 and which have upward extensions provided with slots36, 38 inclined with relation to each other. A transverse pin 40 extendsthrough both slots 36, 38 and is carried at opposite ends by parallel 3links 42 (Figs. 1 and 6) pivotally secured'at their upper ends toparallel arms 44 mounted for free rotary movement on a transverse rod orshaft 46 fast at opposite ends in the frame 20. As will be described,the pin 40 is movable heightwise of the machine so as to open and closethe gripper jaws. Upward movement of the pin 40 in the slots 36, 38closes the gripper 24. The heightwise movement of the pin 40 is producedby rocking the parallel arms 44. To this end each arm 44 has an upwardlyand rearwardly extending projection 48, the two projections 48 beinginterconnected by a web 50. Each projection 48 has secured to it arearwardly extending rod 52 which passes through a boss provided at theupper end of an arm 54, each arm being freely rotatable about the rod46. A spring 56 is mounted on each rod 52 and is confined between theboss of the arm 54 at one end and nuts 58 on the rod at th other end. Aswill be noted, operation of both arms 54 in a clockwise direction, asviewed in Fig. 1, will produce a yielding movement in the same directionof the parallel arms 44, with the result that the pin 40 will beelevated to close the gripper. Thus the gripper is closed by ayieldingly operated mechanism. The two arms 54 are interconnected by aweb 60 (Fig. 6). The right hand arm 54 (as viewed from the front of themachine) is part of a two armed lever 62 (Fig. l) rotatable about therod 46 and carrying at its lower end a cam roll or cam follower 64 heldagainst the periphery of a cam disk 66 on the shaft 28 by a torsionspring 68 (Figs. 3 and 6) coiled about a spacer 69 between the hub ofthe lever 62 and the bearing of th rod 46, one end of the spring 68being in engagement with the lever 62 and the other end with a fixedportion of the frame. Rotation of the cam disk 66 thus causes operationof the transverse pin 40 to open and close the gripper. However, thismotion is utilized not only for opening and closing the gripper but formoving the gripper heightwise of the machine either to tension the upperafter it has been seized by the gripper or to move the gripper into aposition in which it can seize th margin of the upper. As has beenpointed out, in the lowermost position of the pin 40 the gripper jawsare open and, assuming that the gripper itself is positioned at thelower end of its heightwise travel, it is to be noted that the movementof the lever 62 by the cam disk 66 in a clockwise direction, as viewedin Fig. 1, will cause an upward movement of the transverse pin 40, withthe result that the gripper jaws are closed upon the margin of the upperpresented thereto, while the gripper remains in its lowermost position.It is only after the gripper jaws have been firmly closed upon themargin of the upper that the gripper begins its heightwise movement totension the upper heightwise of the last. To accomplish this the upperextension of the gripper jaw 38 is pivoted by a pin "II to an arm (Figs.1 and 6) rotatably mounted on the rod 46. The pin TI is the main supportof the entire gripper 24 which is adapted to move about the pin 'II in adirection transverse to the shoe presented to the machine. The arm 78 isconnected by a link I2 (Fig. l) to a friction device or retarder [4 of aconventional type which functions to prevent an upward movement of thegripper jaws while they are being firmly closed upon the upper. Oncontinued upward movement of the transverse pin 43 after the closing ofthegripper the resistance of the friction device I4 is overcome and thegripper isv moved heightwiseof 4 the machine, moving the arm 10 at thesame time in a clockwise direction (Fig. 1) about the rod 46. Reversely,when the gripper is in its elevated position with the jaws closed,downward movement of the transverse pin 40 serves to open the gripperjaws while the gripper is maintained in its uppermost position due tothe retarding .action of the friction device 14, which action is Thewiper head or throat member To wipe each portion of the upper U over theinsole feather and against the upstanding lip of the insole I after thatportion of the upper has been tensioned by the gripper and is held undertension, there is provided a wiper head 80 (Figs. 1 and 4) which alsofunctions as a throat member or none in that the fastenings are insertedinto the work through that member. The wiper head 80 is of asubstantially rectangular shape having a tapering front end and beingarranged for reciprocating movement substantially in a horizontal pathinto and out of engagement with the shoe presented to the machine. Thewiper head 8:! comprises a main portion 82 (Figs. 4 and 5) which isprovided at its right hand side (as seen from the front of the machine)with a cover plate 84. The wiper head is supported for movement towardand from the work on a front link 86 (Figs. 1 and 2) and a parallel backlink 88, the two links having the same effective length. The upper endsof the links are pivotally connected to the wiper head 80. The lower endof the front link 86 is mounted to rotate freely on a rod 90 secured inthe machine frame and the lower end of the back link 88 is mounted torotate freely on a rod 92 secured in the machine frame. To actuate thewiper head there is provided a bell crank lever I00 (Fig. 2) which actsyieldingly on the front link 86 to advance the wiper head 80 toward thework. One arm of the bell crank lever I69 carries a roll or cam followerI02 engaging a cam groove provided in one face of a cam disk I 64. Thejust mentioned yielding operation of the link 86 by the bell crank leverIDS is accomplished in the following manner: There is provided in thefront link 86 a socket I06 and a similar socket IE8 is provided in theupwardly extending arm of the bell crank lever I00. The two sockets areaxially alined and house a spring I I 0 surrounding a headed bolt I I2-extending from the front side of the link 86 through both sockets andthrough to the rear side of the upwardly extending arm of the bell cranklever I00 where it carries lock nuts bearing against said arm. As

will be noted from an inspection of Fig. 2, movement of the bell crankmember Illll in a counterclockwise direction will cause a yieldingmovement of the link 86 in the same direction to advance the wiper headtoward the work, but movement of the bell crank member I00 in aclockwise direction will produce a positive movement of the link 66 inthe same direction for purposes to be described, this being due to theprovision of the bolt I I2 and the lock nuts carried by it.

It should be noted that, since the two links 86, 88 carrying the wiperhead 88 have the same effective length, a parallel motion results. Therearward movement of the wiper head 88 is adjustably determined by thefollowing mechanism. The back link 88 is provided with a tail piece H4which has a socket H6 carrying a screw I26 secured in place by a nutE22, the lower end of the screw on rearward movement of the wiper head80 being adapted to engage an abutment I I8 provided on the lowerportion of the machine frame.

The wire feeding mechanism The fastenings to be inserted by theillustrated machine are formed therein from a continuous strand offastening material, such as wire, which is fed forwardly in the machinestep by step and the leading end portion of which is severed to form asingle legged straight fastening, The strand of fastening material ispreferably wound on a reel (not shown) which is conveniently mounted forrotation on the machine frame and from which the wire passes throughsuitable guides (not shown) into a wire feeding mechanism.

The leading end portion of the wire, each time the wire has beenadvanced in the machine, is cut off to form a fastening which then istransferred into the line of drive and inserted endwise into the work.

The fastening driving mechanism For inserting fastenings into the workpresented to the machine there is provided a reciprocating driver 262(Figs. 4 and 5) which, in the illustrated example, is extremely thin andof the same gage as the wire from which the fastenings are formed. Thedriver is movable in and with relation to the wiper head 86 and, as fulldisclosed in the above-mentioned application for Letter Patent of theUnited States it is guided and covered all around and over its entirelength during the entire course of its travel. The driver 262 is movablein a bar shaped guiding member 264 of rectangular cross section which isseated flush in a longitudinal recess provided in the back face orinside face of the cover 84. The guiding member 264 has extending alongthe exposed face thereof a groove which serves as the driver passage andwhich is covered or bridged over, as will be presently described. Thedriver 262 is connected to a driver bar 266 which is reciprocated in alongitudinal recess provided in the main portion 82 of the wiper head.To hold the guiding member 264 in place there is provided a stop pin 268(Fig. 5) driven into the cover 84 and abutting the rear end of theguiding member 264. The driver 262 is secured to the driver bar 266 asfollows: The rear end of the driver has a lateral fin 210 which extendsinto a slot provided in one end of a pin 212 carried by the driver bar266. The rear end of the driver 262 is engaged by a hardened pin 214also carried by the driver bar 266 and positioned in tangential relationto the pin 212. The pin 2'f4 is provided with a ridge which extends intothe groove of the guiding member 264 and engages the rear end of thedriver.

It is understood that the machine is provided with mechanism (not shown)adapted to reciprocate the driver so as to cause it to drive a fasteninginto the work or to return into an inoperative retracted position inwhich a new fastening may be transferred into the line of drive in frontof the driver.

The gripper throw-out mechanism To adapt the illustrated machine toinsert fastenings without utilizing the gripper mechanism either toprocess certain portions of the workpiece where the gripper operation isunnecessary or undesired, or to insert fastenings into other types ofwork where no gripper operation at all is required, mechanism isprovided to render the gripper mechanism inoperative and maintain it inan inoperative out-of-the-way position. To this end the gripper jaw 32is provided at its upper portion with a toothed segment 35!! (Fig. 1)which is adapted to be engaged by a locking pawl 352 pivoted to a boss354 provided on the other gripper jaw 36. A torsion spring 355, mountedon the hub of the pawl 352 and having one end engaging the pawl and theother the boss 354, tends to depress the pawl 352 into lockingengagement with the segment 356. The pawl has an upwardly extending arm356 the upper end of which is pivotally connected to a link 358 arrangedfor lengthwise reciprocation and carrying at its rear end a pin 360(Figs. 1 and 6) the opposite ends of which engage slideways provided ina forked tail piece 362 of the arm l6. Sliding movement of the link 358toward the left of Fig. 1 permitsthe spring 355 to move the pawl 352into locking engagement with the segment 358 and sliding movement of thelink 358 toward the right of Fig. 1 lifts the pawl 352 out of engagementwith the segment 350. The link 358 is connected at its rear end by thepin 368 to a latch 364 of substantial length. The rear end of the latch364 is of considerable width, and, in order to maintain the pawl 352 inits elevated inoperative position and thus to maintain the gripperoperative, the hooked rear end of the latch 364 is normally engaged by apawl 366 freely rotatable on a transverse shaft 368 rotatably mounted inthe machine frame. The pawl 366 is biased by a torsion spring 316 whichtends to move the pawl in a clockwise direction, as viewed in Fig. 1,into locking engagement with the latch 364. This movement is limited bya fixed stop pin 3T2 engaging a slot provided in a depending portion ofthe pawl 366. To render the gripper mechanism inoperative the latch 364is elevated out of engagement with the pawl 366 and this is effected bya plate (not shown) secured to the shaft 368 and underlying a portion ofthe rear end of the latch 364. Secured to the shaft 368 and spaced fromthe just mentioned plate is a similar plate 316 which overlies the endof a treadle rod 318 upward movement of which, when permitted, causesthe plate to be raised with the result that the latch 364 is freed. Assoon as the latch 364 is disengaged from the pawl 366 the spring 355becomes active to slide the link 358 toward the left of Fig. 1 and todepress the pawl 352 into locking engagement with the segment 350 so asto prevent the gripper from closing; Mechanism is provided to preventthe upward movement of the treadle rod 318, even though the rod may bestressed in that direction, until a predetermined point in the cycle ofgripper operation has been reached, namely when the gripper issubstantially in its down position and its laws are open. In thisposition of the gripper the cam roll 64 is near the low portion of thecam disk 66. The purpose of this arrangement is to insure that thegripper is open when it is being rendered inoperative, the gripper jawsbeing locked in their open position, whereupon the gripper is elevatedinto its inoperative position and held in that position, as will bedescribed. To accomplish this the treadle rod 318 has secured to it acollar 380 the right side of which is provided with a shoulder, asillustrated in Fig. 1. With the collar 380 cooperate two pawls, namely,a left hand pawl 382, adapted to engage beneath the collar 38!] and holdit and thus the treadle rod 318 in an elevated position and a right handpawl 384 which normally engages the shoulder portion of the collar 388so as to prevent upward movement of the collar and the treadle rod 318..The two pawls 382, 38 5 are biased by springs. (not shown) toward thecollar 38!! and are pivotally secured to a bracket 385 mounted in themachine frame. To operate the pawls there is provided a pin 388extending laterally from a link 39!] the front end of which is pivotallysecured to the gripper operating cam lever 62' and the rear end of whichis slotted, the slot being engaged by a pin 392 extending laterally fromthe bracket 386, this to permit lengthwise reciprocation of the link 390upon rocking movement of the cam lever 62. As will'be described, the pin388, when being reciprocated by the link 390, is adapted to releaseeither pawl 382 or 384 from engagement with the collar 385. For thepurpose of maintaining the gripper mechanism locked out there is securedon the treadle rod 3 18 a collar 394 which is adapted on upward movementof the treadle rod to engage a latch 396 pivotally secured at its righthand end (Fig. 1') to the bracket 385 and normally maintained in a lowposition against a stop pin 39! by a spring 398. The latch 396 whenraised by the collar 394 is adapted to engage behind a shoulder 405provided on the link 390 when that link is in its forward position inwhich the gripper is elevated, this preventing the link from returning.Thus the gripper is locked in its elevated inoperative position.

In the position of the machine parts illustrated in Fig. l, the grippermechanism is operative and the gripper throw-out mechanism isinoperative with the treadle rod 318 down and and its upward movementprevented by the engagement of the pawl 334 with the collar 380'. Let itbe assumed now that upward pressure is applied to the treadle rod 318.Nothing happens until the low portion of the cam 55 is opposite the camfollower E4 and the link 39!! has been moved rearwardly by the cam lever62, causing the pin 388 to engage the pawl 384 and knock it ofi thecollar 388. Now the treadle rod 318 is free to move up. As will benoted, the upward movement of the treadle rod is thus possible only whenthe low portion of the cam 66 is opposite theroll 64 or, in other words,when the gripper is down and open. The upward movement of the treadlerod 318 accomplishes two things. First, the plate 316 is elevated,freeing the latch 36 to enable the torsion spring 355 to depress thepawl 352 into locking engagement with the toothed segment 353.Accordingly, the gripper cannot be closed. The other function exercisedby the treadle rod is, as already described, the elevation of the latch396 into a position in which, upon forward movement of the link 39!, asthe cam roll 64 approaches the high portion of the cam 66, it can snapbehind the shoulder 43B and thus hold the cam lever 62 locked out in aposition similar to that shown in Fig. 1... It should be noted that thisoutward movement of the link 390 by the corresponding movement of thecam lever 62 in a clockwise direction, as viewed in Fig. 1, causeselevation of the gripper into its inoperative position with the gripperjaws open, the gripper 8 being then maintained in. that position byreason of. the: locking of the link 39!] against rearward movement bythe. latch 396. However, the link 395 is not locked: in. its frontmostposition, thus enabling the pawl 382 to engage beneath the collar 38!?to hold the treadle rod 318 up. Thus, a slight forward movement of thelink 39!) occurs even while the. gripper mechanism is locked out whenthecam roll 54 passes over the highest portion; of. the cam 56 with theresult that the pawl 382: is moved out of engagement with the collar 338once during each cycle, namely when the highest point of the cam 65 isopposite the cam roll 64. Accordingly, the treadle rod 318 can belowered again only at that time. When it. is desired to throw thegripper mechanism into. operation, the treadle (not shown) operating thetreadle rod 3'18 is released but, as pointed out, the treadle rod cannotmove down since it is locked by the pawl 38!. The pawl 382 becomesautomatically unlocked when. the cam roll 64 passes over the highestportion of the cam 66, causing the above mentionedslight forwardmovementof the link 390 and the pawl releasing pin 388. As the treadle rod 318goes down the collar 394 also is lowered, permitting the spring 398 topull the latch 396 out of engagement with the shoulder 453, thusenabling the link 390 again tomove rearwardly in the machine andaccordingly permitting the gripper to descend and to be operated in thenormal way. Of course, the lowering of the treadle rod 318 also causesthe plate 316 to be lowered, with the result that the latch 354 islowered. To unlock the gripper jaw 32 by raising' the locking pawl 352there is secured on a rearward extension of the wiper head 88 a catch562 (Figs. 1 and 2) which, during the rearward movement of the wiperhead, engages the hooked end ofthe latch 364 and pulls the latchrearwardly into. locking engagement with the pawl 366', thereby slidingthe link 358 rearwardly in the machine and elevating the pawl 352against the-pressure of its spring 355.

Having described my invention, what I claim as new and desire to secureby Letters Patent of the United States is:

LIna shoe lasting machine, a lasting gripper adapted to tension a shoeupper on a last heightwise of the last, a throat member movable intoengagement with the tensioned upper, a driver movable in the throatmember to insert fastenings into the work so as to secure the tensionedupper in lasted relation thereto, means for both moving the gripperheightwise of the machine and for opening: and closing thegripper, andoperator controlled means adapted to lock the gripper against closingand to arrest the gripper in an elevated position. without affecting theoperation of the machine.

2. In a. shoe lasting machine, a lasting gripper adapted to tension ashoe upper on a last heightwise of the last, a throat member movableinto engagement with the tensioned upper, a driver movable in. thethroat member to insert fastenings into the work so as to secure thetensioned upper in lasted relation thereto, means for both moving thegripper heightwise of the machine and for opening and closing thegripper, and operator controlled means adapted to lock the gripperagainst closing and to arrest thegripper in an elevated position, andmeans permitting the operation of said operator controlled means onlywhen the gripper is substantially in its lowermost position.

3. In a shoe lasting machine, a lasting gripper adapted to tension ashoe upper on a last heightwise of the last, a throat member movableinto engagement with the tensioned upper, a driver movable in the throatmember to insert fastenings into the work so as to secure the tensionedupper in lasted relation thereto, means for both moving the gripperheightwise of the machine and for opening and closing the gripper, meansfor arresting the gripper in an inoperative e1evated and open position,operator controlled means for initiating the operation of said arrestingmeans, and means for preventing the operation of said operatorcontrolled means unless the gripper is substantially in its lowermostposition.

4. In a shoe lasting machine, a lasting gripper adapted to tension ashoe upper on a last height- Wise of the last, a throat member movableinto engagement with the tensioned upper, a driver movable in the throatmember to insert fastenings into the work so as to secure the tensionedupper in lasted relation thereto, gripper operating means for bothmoving the gripper heightwise of the machine and for opening and closingthe grip-per, a cam lever adapted to actuate the gripper operatingmeans, a cam provided with a high and a low portion and adapted tooscillate the cam lever, means for arresting the gripper in aninoperative and open position, and means for releasing the gripper, thereleasing means being operative only when the high portion of the cam isacting on the cam lever.

5. In a shoe lasting machine, a lasting gripper adapted to tension ashoe upper on a last heightwise of the last, a throat member movableinto engagement with the tensioned upper, a driver movable in the throatmember to insert fastenings into the work so as to secure the tensionedupper in lasted relation thereto, gripper operating means for bothmoving the gripper heightwise of the machine and for opening and closingthe gripper, a cam lever adapted to actuate the gripper operating means,a cam provided with a high and a low portion and adapted to oscillatethe cam lever, means for arresting the gripper in an inoperativeposition, means for preventing the operation of the arresting meansunless the low portion of the cam is acting on the cam lever, means forreleasing the gripper out of inoperative position, and means forpreventing the operation of the releasing means unless the high portionof the cam is acting on the cam lever.

6. In a shoe lasting machine, a lasting gripper adapted to tension ashoe upper on a last heightwise of the last, a throat member movableinto and out of engagement with the work, a driver movable in the throatmember to insert fastenings into the work so as to secure the tensionedupper in lasted relation thereto, locking means adapted to prevent theclosing of the gripper, cam operated means adapted to move the opengripper into an inoperative position and to hold the gripper in thatposition, operator controlled means for initiating the operation of boththe aforementioned locking means and the cam operated means, meansautomatically active at a predetermined point in each cycle of operationto release the gripper from its inoperative position, and meansassociated with the throat member and adapted on movement of the throatmember out of engagement with the work to render the locking meansinoperative.

ROBERT H. LAWSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

Number Name Date 456,225 Sinning July 21, 1891

